When Tokyo TV asked a studio full of petite middle-school girls to discuss anger management, the producers found streaks of violence to match the blonde ones in the teens' hair. Behind giggles, the first girl confessed she liked nothing better than to kick boys hard in the groin. The malevolent girl then stepped out to demonstrate on a man-sized teddy.
On surveying the other girls, the producers found this was their favourite way to let off steam, closely followed by screaming wildly and ripping pages from books.
Japanese pupils spend long hours in class, and exam pressures familiar to English children mean they often get little sleep. A ministry of education study shows that 20 per cent feel "frustrated or irritated" daily.
But it could be worse: a 16- year-old Kyoto girl was arrested this week for killing her policeman father with an axe. "He irritated me," she said.